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About this tool
Free falling-blocks puzzle game — stack pieces, clear lines, and chase a high score.
Block Stacker is a falling-block puzzle game on the classic 10-column by 20-row well, where the seven tetromino shapes (I, O, T, S, Z, J, L) drop from a shuffled seven-bag so every shape appears once before any repeats. Clearing one, two, three or four rows at a time scores 100, 300, 500 or 800 points multiplied by your level, and the level rises every ten lines cleared, cutting the gravity interval by about 18% each time. It has a hold slot, a three-piece preview queue, a ghost outline showing where the piece will land, and wall kicks so rotations near the wall still work.
Open Block Stacker on AltFTool — it loads instantly in your browser.
Add your input to the workspace.
Adjust the options until the result looks right.
Copy or download the output and put it to work.
Pieces come from a shuffled bag of all seven, so you can never be starved of an I-piece for long the way pure random generation allows.
You see exactly where the piece lands before committing, and can park an awkward shape in hold until it is useful.
Eight wall-kick offsets are tried in order when a rotation would collide, so turning against a wall or a stack usually still succeeds.
Clearing 1, 2, 3 or 4 lines at once awards 100, 300, 500 or 800 points, multiplied by your current level. Soft dropping adds 1 point per cell and hard dropping adds 2 per cell, so a four-line clear at level 5 is worth 4,000 points against 500 for four single clears.
The level goes up every 10 lines cleared, and each level multiplies the gravity interval by 0.82 — starting near 900 ms per row at level 1 and bottoming out at 70 ms, which is reached around level 14.
Arrow keys or WASD to move and rotate, Space for a hard drop, C to hold a piece, and P to pause. On touch, the on-screen buttons work, tapping the board rotates, and a downward swipe of more than about 48 pixels hard-drops.
Yes, your best score is stored in the browser and also recorded if you leave mid-game, so an unfinished run still counts. It lives on that device and browser, so it will not follow you to another machine.